Light emitting module and backlight unit having the same

ABSTRACT

A light emitting module includes a plurality of light emitting diodes; and a module substrate having a wiring portion disposed with the plurality of light emitting diodes, and a heat radiation portion folded from the wiring portion and disposed under the plurality of light emitting diodes, wherein the plurality of light emitting diodes includes a first light emitting diode disposed on a first outer region of the wiring portion, a second light emitting diode disposed on a second outer region of the wiring portion, and a third light emitting diode disposed on a center of the wiring portion, and in the heat radiation portion of the module substrate, the width between the center of the wiring portion and the end of the heat radiation portion is wider than that between the first outer region of the wiring portion and the end of the heat radiation portion.

The present application claims priority under 35 U.S.C. §119(a) ofKorean Patent Application No. 10-2011-0084799 filed on Aug. 24, 2011,which is hereby incorporated by reference in its entirety.

BACKGROUND

Embodiments relate to a light emitting module and a backlight unithaving the same.

As information processing technology evolves, displays such as LCD, PDPand AMOLED has been widely used. The LCD among the displays requires thebacklight unit generating light to display the images.

In the light emitting module, a plurality of light emitting diodes aremounted on the substrate, and driven by supplying external power sourcethrough a connector.

SUMMARY

Embodiments provide a light emitting module having a new structure and abacklight unit having the same.

Embodiments provide a light emitting module forming differently an areaof the heat radiation portion of the module substrate according a regionand a backlight unit having the same.

Embodiments provides provide a light emitting module formed so that theheat radiation portion of the module substrate is folded from the wiringportion mounted with the light emitting diode and the area of the heatradiation portion and gravity direction are in inverse proportion toeach other, and a backlight unit having the same.

Embodiments provides a light emitting module including a plurality oflight emitting diodes; and a module substrate having a wiring portiondisposed with the plurality of light emitting diodes, and a heatradiation portion folded from the wiring portion and disposed under theplurality of light emitting diodes, wherein the plurality of lightemitting diodes includes a first light emitting diode disposed on afirst outer region of the wiring portion, a second light emitting diodedisposed on a second outer region of the wiring portion, and a thirdlight emitting diode disposed on a center of the wiring portion, and awidth between the center of the wiring portion and the end of the heatradiation portion is wider than that between the first outer region ofthe wiring portion and the end of the heat radiation portion, in theheat radiation portion of the module substrate.

Embodiments provides a light emitting module including a plurality oflight emitting diodes; and a module substrate having a wiring portiondisposed with the plurality of light emitting diodes, and a heatradiation portion folded from the wiring portion and disposed under theplurality of light emitting diodes, wherein the plurality of lightemitting diodes includes a first light emitting diode disposed on afirst outer region of the wiring portion, a second light emitting diodedisposed on a second outer region of the wiring portion, and a thirdlight emitting diode disposed on a center of the wiring portion, and awidth between the center of the wiring portion and the end of the heatradiation portion is wider than that between the first and second outerregions of the wiring portion and the end of the heat radiation portion,in the heat radiation portion of the module substrate.

Embodiments provides a backlight unit including a bottom cover includinga bottom portion and a first side portion folded from the bottomportion; a light guide plate on the bottom cover; and a light emittingmodule comprising a module substrate including a wiring portion disposedon the inside of the first side portion of the bottom cover andcorresponding to at least one side of the light guide plate, and a heatradiation portion folded from the wiring portion and disposed on thebottom portion of the bottom cover; and a plurality of light emittingdiodes disposed on the wiring portion of the module substrate andcorresponding to at least one side of the light guide plate, wherein theplurality of light emitting diodes includes a first light emitting diodedisposed on a first outer region of the wiring portion, a second lightemitting diode disposed on a second outer region of the wiring portion,and a third light emitting diode disposed on a center of the wiringportion, and a width between the center of the wiring portion and theend of the heat radiation portion is wider than that between the firstouter region of the wiring portion and the end of the heat radiationportion, in the heat radiation portion of the module substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded prospective view of the display apparatus of theembodiment.

FIG. 2 is a partially side cross-sectional view of a backlight unit ofFIG. 1.

FIG. 3 shows an example for a light emitting module of FIG. 2.

FIG. 4 shows another example for the light emitting module of FIG. 2.

FIG. 5 shows the light emitting module according to a first embodiment.

FIG. 6 shows the light emitting module according to a second embodiment.

FIG. 7 shows the light emitting module according to a third embodiment.

FIG. 8 shows the light emitting module according to a fourth embodiment.

FIG. 9 shows an example for a light emitting diode of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the description of the embodiment, in a case where each substrate,frame, sheet, layer or pattern and the like is described to be formed“on” or “under” thereof, “on” or “under” also means one to be formed“directly” or “indirectly (through other component)” to component. Also,the criteria regarding “on” or “under” of each component will bedescribed based on the drawings. In the drawing, the size of eachcomponent may be exaggerated to describe, and does not mean the sizethat is in fact applied.

FIG. 1 is an exploded prospective view of displays of the embodiment.

Referring to FIG. 1, the display apparatus 100 includes a display panel10 displaying images, and a backlight unit 20 providing light to thedisplay panel 10.

The backlight unit 20 includes a light guide plate 70 providing surfaceilluminant to the display panel 10, a reflection member 45 reflectingleaked light, a light emitting module 30 providing the light at edgeregion of the light guide plate 70, and a bottom cover 40 forming theappearance of the bottom of the display apparatus 100.

Although not shown in the drawing, the display apparatus 100 may includea panel supporter supporting the display panel 10 in the bottom thereof,and a top cover forming the edge of the display apparatus 100 andsurrounding the circumference of the display panel 10.

Although not shown in detail, the display panel 10 includes, forexample, lower and upper substrates facing each other and coupled to bemaintained with a uniform cell gap, and a liquid crystal layer (notshown) interposed between the two substrates. The lower substrate isformed with a number of gate lines and a number of data linesintersecting with a number of gate lines, and thin film transistors(TFT) may be formed in the intersecting region of the gate line and thedata line. The upper substrate may be formed with color filters. Thestructure of the display panel 10 is not limited thereto, and thedisplay panel 10 may have various structures. For another example, thelower substrate may include the thin film transistor and the colorfilter. Further, the display panel 10 may be formed by various types ofthe structures according to the method driving the liquid crystal layer.

Although not shown, the edge of the display panel 10 may be includedwith a gate driving printed circuit board (PCB) supplying scan signal tothe gate lines and a data driving printed circuit board (PCB) supplyingdata signal to the data lines.

At least one of a top surface and a lower surface of the display panel10 may be disposed with polarization films (not shown). A lower portionof the display panel 10 is disposed with an optical sheet 60, and theoptical sheet 60 may be included in the backlight unit 20, and mayinclude at least one prism sheet or/and diffusion sheet. The opticalsheet 60 may be removed, and is not limited thereto.

Light that is incident is uniformly diffused by the diffusion sheet, andthe diffused light may be condensed into the display panel by the prismsheet. Here, the prism sheet may be selectively configured by ahorizontal or/and vertical prism sheet, at least one illuminationreinforcement sheet etc. The kind or number of the optical sheet 60 maybe added or deleted within the technical range of the embodiment, and isnot limited thereto.

The light emitting module 30 may be disposed on an inside of a firstside portion 42 of the sides of the bottom cover 40. For anotherexample, the light emitting module 30 may be disposed on the sideportions different from each other in the bottom cover 40, for example,both sides or all sides, and is not limited thereto.

The light emitting module 30 includes a module substrate 32, and aplurality of light emitting diodes 34 arranged in one surface of themodule substrate 32.

The module substrate 32 may include any one of resin-based printedcircuit board, metal core PCB, flexible PCB, ceramic PCB, and FR-4substrate. The inside of the module substrate 32 may be included withthe printed circuit boards having metal layers.

The plurality of light emitting diodes 34 are corresponded in thedirection of a light entrance edge of the light guide plate 70 at apredetermined pitch, and arranged along a first direction X of themodule substrate 32. At least one of the plurality of light emittingdiodes 34 may emit, for example, at least one of white, red, green, andblue. In the embodiment, the light emitting diode emitting the lighthaving at least one color may be used, or it is possible to use acombination of the light emitting diodes emitting a plurality of colors.

The light emitting diodes 34 may include light emitting chips usinggroup III-V compound semiconductors, and molding members protecting thelight emitting chips. The molding member may be added with at least onekind of a phosphor, and is not limited thereto. The light emitting chipsmay emit visible wavelengths or ultraviolet light.

The light emitting diodes 34 may be disposed by at least one row, andmay be arranged at regular or irregular intervals.

The module substrate 32 includes a wiring portion 32A and a heatradiation portion 32B, the light emitting diodes 34 is disposed on thewiring portion 32A, the heat radiation portion 32B is folded from thewiring portion 32A and may be disposed with angles (for example: 85˜95°)almost vertical to the wiring portion 32A, for example, substantiallyorthogonally. The module substrate 32 may be formed in the shape of, forexample, ‘L’ character. The heat radiation portion 32B may not bedisposed with the light emitting diodes 34, and may be formed of theregion folded from the wiring portion 32A. The heat radiation portion32B is disposed under the plurality of light emitting diodes 34, and isextended longer than the thickness of the light emitting diodes 34.

Here, in the module substrate 32, X-axis direction may be defined in thelength direction thereof, Z-axis direction may become the widthdirection of the heat radiation portion 32B, and Y-axis direction maybecome the width direction of the wiring portion 32A. The Z-axisdirection is orthogonal to the Y-axis direction, and the Z-axisdirection and the Y-axis direction are orthogonal to the X-axisdirection.

The heat radiation portion 32B is showed as the folded structure in alower direction of the wiring portion 32A, but may be folded so as to befaced each other in both directions (for example, top and lowerdirections) of the wiring portion 32A, and is not limited thereto.

The width of the heat radiation portion 32B may be wider than the widthof the wiring portion 32A, and the width may be controlled inconsideration of the heat radiation efficiency. The thickness of thewiring portion 32A may be formed thicker than that of the heat radiationportion 32B.

The wiring portion 32A of the module substrate 32 may be connected to afirst side portion 42 of the bottom cover 40 and a connecting member 50.The connecting member 50 may include adhesive member. The wiring portion32A of the module substrate 32 may be connected to the first sideportion 42 using a fastening member rather than the connecting member.

The wiring portion 32A of the module substrate 32 may be disposed withconnectors. The connectors may be disposed on at least one of the topand lower surfaces of the module substrate 32, and is not limitedthereto.

At least one side (that is, the light entrance edge) of the light guideplate 70 is corresponded with the plurality of light emitting diodes 34disposed on the wiring portion 32A of the module substrate 32. The heatradiation portion 32B of the module substrate 32 is corresponded to thelower surface of the light guide plate 70, and may be disposed inparallel with the lower of the module substrate 32. The light generatedfrom the plurality of light emitting diodes 34 is incident on at leastone side (that is, the light entrance edge) of the light guide plate 70.The plurality of light emitting diodes 34 may be disposed on the wiringportion 32A by top view method, and is not limited thereto.

The light guide plate 70 may be formed in a shape of a polygon includinga top surface on which the surface illuminant is generated, a lowersurface opposite to the top surface, and at least four sides. The lightguide plate 70 is formed of transparent material, and may contain, forexample, one of acrylic resin such as polymethyl metaacrylate (PMMA),polyethylene terephthlate (PET), poly carbonate (PC), cycloolefincopolymer (COC) and polyethylene naphthalate (PEN) resin. The lightguide plate 70 may be formed of extrusion molding, and is not limitedthereto.

The top/on/and lower surface of the light guide plate 70 may be formedwith reflection patterns (not shown). The reflection patterns includingpredetermined patterns, for example, the reflection patterns or/andprism patterns reflect or/and irregularly reflect the light that isincident, and therefore, the light may be regularly irradiated throughthe entire surface of the light guide plate 70. The lower surface of thelight guide plate 70 may be formed of the reflection patterns, and thetop surface may be formed by the prism patterns. The inside of the lightguide plate 70 may be added with scattering agents and is not limitedthereto.

A reflection member 45 is disposed under a lower portion of the lightguide plate 70. The light proceeding under the light guide plate 70 isreflected in the direction of the display panel by the reflection member45. A portion of the reflection member 45 is disposed under an incidentlight portion of the light guide plate 70, or may be disposed under theplurality of the light emitting diodes 34. The portion of the reflectionmember 45 may be disposed between the light guide plate 70 and the heatradiation portion 32B. The reflection member 45 may be formed of, forexample, PET, PC, PVC resin, etc., but is not limited thereto. Thereflection member 45 may be the reflection layer formed on the topsurface of the bottom cover 40, but is not limited thereto. The lightleaked into the lower surface of the light guide plate 70 may beincident again into the light guide plate 70 by the reflection member45. As a result, the light efficiency of the backlight unit 20 isimproved, and problems such as the lowering of the light characteristicand the generation of dark portions may be prevented.

The bottom cover 40 includes an receiving portion 41 opened with thetop, and the receiving portion 41 may be accommodated with the lightemitting module 30, the optical sheet 60, the light guide plate 70, andthe reflection member 45. The bottom cover 40 may be selectively formedamong the metal having high heat radiation efficiency, for example,aluminum (Al), magnesium (Mg), zinc (Zn), titanium (Ti), tantalum (Ta),hafnium (Hf), niobium (Nb) and their selective alloys. The bottom cover40 may be formed of the resin material, but is not limited thereto.

The receiving portion 41 of the bottom cover 40 may be sequentiallystacked with the reflection member 45, the light guide plate 70, and theoptical sheet 60, and the light emitting module 30 is corresponded toone side of the light guide plate 70 in the first side portion 42 of thebottom cover 40.

A bottom portion 41A of the bottom cover 40 is formed with a recessportion 41B, and the recess portion 41B is coupled with the heatradiation portion 32B of the module substrate 32. The recess portion 41Bmay be formed with the same depth as the thickness of the heat radiationportion 32B and the same width as that of the heat radiation portion 32Band is not limited thereto.

In the embodiment, the recess portion 41B is disposed in the portionfolded from the first side portion 42 of the bottom portion 41A of thebottom cover 40, but the recess portion 41B may be not formed.

When disposing the display apparatus 100, it is possible to allow an UPdirection to be disposed upwardly. The heat generated from the lightemitting diodes 34 of the light emitting module 30 is moved in the UPdirection, that is, in the direction opposite to gravity by such adisposing direction. In the embodiment, the heat radiation portion 32Bof the light emitting module 30 may further improve the heat radiationefficiency by more widening the area of the region disposed in thedisposing direction of the display apparatus 100, that is, in thedirection opposite to gravity. Further, for optimal heat radiationefficiency according to the disposing direction of the display apparatus100 and the distribution of the heat generated from a plurality of lightemitting diodes 34, the area and the width of the heat radiation portion32B are considered.

Referring to FIGS. 2 and 3, the module substrate 32 includes a metallayer 131, an insulation layer 132 on the metal layer 131, an wiringlayer 133 on the insulation layer 132, and a protection layer 134 on thewiring layer 133.

The metal layer 131 contains at least one of Al, Cu, and Fe, is disposedon the entire lower surface of the module substrate 32, and therefore,is used as the heat radiation plate. The metal layer 131 may use theplate having copper (Cu) material, for example, for the fold and theheat radiation efficiency. The metal layer 131 may have the thickness of0.8 mm˜1.5 mm. A width of the lower surface of the metal layer 131 maybe formed as the same width as that of the module substrate 32. The areaof the lower surface of the metal layer 131 may be formed as the samearea as that of the module substrate 32.

The metal layer 131 may be include a first heat radiation portion 131Aand a second heat radiation portion 131B by folding a flat structure ofFIG. 3 based on the boundary between a second region B2 and a thirdregion B3. Here, the second region B2, which is a buffer regionprotecting the folded portion, may be formed in the range of 0.8 mm ormore, for example, 0.8˜1 mm. The first region B1 becomes the wiringpattern region of the wiring portion 32A.

The insulation layer 132 is disposed on the metal layer 131, theinsulation layer 132 contains preimpregnated materials, and may contain,for example, epoxy resin, phenol resin, and unsaturated polyester resinsetc. The insulation layer 132 may have the thickness of 80˜100 μm, andthe width thereof may be formed narrower than the width (or area) of themetal layer 131.

The wiring layer 133 includes the circuit pattern, contains at least oneof Cu, Au, Al, and Ag, and may use, for example, copper (Cu). The wiringlayer 133 may have the thickness of 25˜70 μm, may be formed thinner thanthe thickness of the insulation layer 132, and is not limited thereto.

A protection layer 134 is disposed on the wiring layer 133, theprotection layer 134 includes solder resist, and the solder resistprotects the region except the pad on the top surface of the modulesubstrate 32. The protection layer 131 may have the thickness of 15˜30μm. The module substrate 32 may be formed with via holes, but is notlimited thereto. In another example, the module substrate 32 may bedisposed with a plurality of wiring layers, and an insulation layer maybe further disposed between the plurality of wiring layers.

The light emitting diodes 34 are mounted on the wiring layer 133 of themodule substrate 32, and the light emitting diodes 34 may be disposed asseries, parallel, or mixed series-parallel structures by the circuitpattern of the wiring layer 133.

The module substrate 32 includes the wiring portion 32A and the heatradiation portion 32B, and the wiring portion 32A is formed of a stackedstructure configured with the metal layer/the insulating layer/thewiring layer/the protection layers (131/132/133/134), and the heatradiation portion 32B is formed of the metal layer 131. Here, the metallayer 131 includes a first heat radiation portion 131A and a second heatradiation portion 131B, the first heat radiation portion 131A becomes abottom layer of the wiring portion 32A, and the second heat radiationportion 131B becomes the heat radiation portion 32B. The second heatradiation portion 131B may have a width wider than the first heatradiation portion 131A. The first heat radiation portion 131A and thesecond heat radiation portion 131B may be formed as the same thickness,and is not limited thereto.

A gap H1 between the top surface of the second heat radiation portion131B and the insulation layer 132 may be formed in the range of 0.8 mm˜1mm, and the insulation layer 132 is spaced apart from the folded portionbetween the first heat radiation 131A and the second heat radiationportion 132B by such the gap H1, thereby to improve the problem such asthe generation of dust by the insulation layer 132 or the lowering ofthe heat radiation effects. This reduces the region occupied with theinsulation layer 132 among the region on the metal layer 131, thereby toprevent the lowering of the heat radiation effect when the insulationlayer 132 covers the metal layer 131. Further, when the insulation layer132 is disposed on the folded portion, cracks occur in the foldedportion, or to affect the circuit pattern may be prevented.

Further, the insulation layer 132 is spaced apart from the foldedportion between the heat radiation portion 32B and the wiring portion32A, such that the gap between the wiring portion 133 and the foldedportion may be further reduced. The reduction of such a gap may reducethe thicknesses of the light emitting module 30 and the backlight unit20 including the same.

The top surface of the heat radiation portion 32B is disposed as thesame plan as the bottom surface of the bottom cover 40 or may bedisposed higher or lower than the bottom surface of the bottom cover 40,and is not limited thereto.

The height H2 of the light emitting module 30, which is the distancefrom the lower surface of the heat radiation portion 32B to the topsurface of the module substrate 32, may be formed in the range of 9mm˜13 mm, and is not limited thereto.

An adhering member 50 is disposed between a first side portion 42 of thebottom cover 40 and the wiring portion 32A of the module substrate 32,and the wiring portion 32A of the module substrate 32 is adhered to asecond side portion 42 of the bottom cover 40 by the adhering member 50.The recess portion 41B formed in the bottom portion 41A of the bottomcover 40 may be adhered with the heat radiation portion 32B of themodule substrate 32 by the adhering member 51. The bottom portion 41A ofthe bottom cover 40 may not be formed with the recess portion 41B, andis not limited thereto.

In the embodiment, when the heat is generated from the light emittingdiode 34, some heat is conducted through the first heat radiationportion 131A of the module substrate 32 to perform the heat radiationinto the path F0 through the first side portion 42 of the bottom cover40, and the other heat is conducted into the second heat radiationportion 131B of the module substrate 32 to perform the heat radiationinto the paths F1 and F2 through the bottom portion 41A of the bottomcover 40.

FIG. 4 is another example of the light emitting module.

In the light emitting module of FIG. 4, the metal layer 131 and theinsulation layer 132 of the module substrate 32 may be formed as thesame width. The entire top surface of the metal layer 131 is formed withthe insulation layer 132, and the insulation layer 132 may reinforce thestrength of the metal layer 131. Further, when manufacturing theinsulation layer 132, since the top surface of the metal layer is notexposed, there is an effect that separate mask layers are not disposedon the metal layer.

FIG. 5 is a prospective view showing the light emitting module accordingto a first embodiment.

In the light emitting module 30 of FIG. 5, the closest light emittingdiode to the first side S1 of the heat radiation portion 32B is definedas a first light emitting diode 34A, and the closest light emittingdiode to the second side S2 opposite to the first side S1 of the heatradiation portion 32B is defined as a second light emitting diode 34B,and the light emitting diodes disposed on a center of the region betweenthe first light emitting diode 34A and the second light emitting diode34B may be defined as a third light emitting diode 34C, among theplurality of light emitting diodes 34. Further, the first light emittingdiode 34A is disposed on the first outer region of the wiring portion32A, the second light emitting diode 34B is disposed on the second outerregion of the wiring portion 32A, and the third light emitting diode 34Cmay be disposed on the center of the wiring portion 32A. The first outerregion and the second outer region may be the regions adjacent to thesides opposite to each other in the wiring portion 32A. Here, a positionof the first light emitting diode 34A is down direction, and theposition of the second light emitting diode 34B is up direction.Further, an interval T1 between the light emitting diodes 34 may be thesame or different in part, and is not limited thereto. The plurality oflight emitting diodes 34 may be disposed on a line having the samecenter.

The width D2 of the second side S2 of the heat radiation portion 32B,which is an interval between the wiring portion 32A and a third side S3of the heat radiation portion 32B, may have the width wider than thewidth D1 of the first side S1 of the heat radiation portion 32B adjacentto the first outer region of the wiring portion 32A. Further, the widthD2 of the top surface of the heat radiation portion 32B corresponding toa lower portion of the second light emitting diode 34B, which is aninterval between a second outer region of the wiring portion 32A and thethird side S3 of the heat radiation portion 32B, may have the widthwider than the width D1 of the top surface of the heat radiation portion32B corresponding to a lower portion of the first light emitting diode34A. Here, the widths D1 and D2 become an interval between the wiringportion 32A and the end of the heat radiation portion 32B, that is, thethird side S3. The widths D1 and D2 of each side S1 and S2 of the heatradiation portion 32B may be the width of the top surface adjacent toeach of the sides S1 and S2.

The third side S3, which is surface between the first side S1 and thesecond side S2 of the heat radiation portion 32B, may be formed as theinclined surface for the first side S1 or/and the second side S2. Thethird side S3 may be formed by a subsequent surface.

In the top surface 131-1 of the heat radiation portion 32B, the intervalbetween the first light emitting diode 34A and the third side S3 is thenarrowest, the interval between the second light emitting diode 34B andthe third side S3 is wider than the interval between the first lightemitting diode 34A and the third side S3, and is the widest in theregion of the top surface 131-1.

Thus, the area of the heat radiation 32B is gradually disposed widelytoward the second light emitting diode 34B, such that the heat may becentered on the second and third light emitting diodes 34B and 34Crather than the first light emitting diode 34A disposed in the directionin which the heat proceeds, thereby to have uniform heat distribution inthe heat radiation 32B by different area of the heat radiation portion32B.

As another example, the heat radiation portion 32B may include unevenstructures. In the uneven structures, the lower portion of the regionbetween the second light emitting diode 34B and the third light emittingdiode 34C is formed with at least one of the concave portion or theconvex portion, thereby to increase the area of the heat radiationportion 32B. The uneven structures may be formed in a shape of stripe orpolygon in the third direction S3 of the heat radiation portion 32B fromthe wiring portion 32A, and may be disposed in one or a plurality of.

FIG. 6 is a perspective view showing the light emitting module accordingto a second embodiment.

Referring to FIG. 6, the light emitting module 32 may be classified intoa lower first region A1 and an upper second region A2 on the center ofthe top surface 131-2 of the heat radiation portion 32B. The loweringfirst region A1 is formed of a first width D1, and the upper secondregion A2 may be formed of a second width D2.

The side S3 of the heat radiation portion 32B includes first surfacesS32 disposed at right angles for the first side S1 and the second sideS2, and a second surface S34 disposed between first surfaces S32 and inparallel with the second side S2. A corner portion between the firstsurface S32 and the second surface S34 may be formed of a curved surfaceor may be folded at a right angle, and is not limited thereto.

The second region A2 of the heat radiation portion 32B, which is theregion between the second and third light emitting diodes 34B and 34C,and the interval between the second light emitting diodes 34B and thethird side S3 of the heat radiation portion 32B, may be formed of thewidth D2 of the second side S2.

The first region A1 of the heat radiation portion 32B, which is theregion between the first and third light emitting diodes 34A and 34C andthe interval between the first light emitting diodes 34A and the thirdside S3 of the heat radiation portion 32B, may be formed of the width D1of the first side S1.

The structures may efficiently heat-radiate when the heat generated fromthe plurality of light emitting diodes 34 is further concentrated in thecenter of the display apparatus.

As another example, the second region A2 of the heat radiation portion32B may include uneven structures. In the uneven structures, the lowerportion of the region between the second light emitting diode 34B andthe third light emitting diode 34C is formed with at least one of theconcave portion or the convex portion, thereby to increase the area ofthe heat radiation. The uneven structures may be formed in a shape ofstripe or polygon in the third direction S3 of the heat radiationportion 32B from the wiring portion 32A, and may be disposed in one or aplurality of.

FIG. 7 is a prospective view showing the light emitting module accordingto a third embodiment.

Referring to FIG. 7, in the heat radiation portion 32B of the lightemitting module 32, the area and width of the top surface 131-3 isformed of the structure increased gradually in a step type toward the UPdirection according to the region A11 to A14. Further, the third side S3of each of the region A11 to A14 may be gradually widened from the firstside S1 direction toward the second side S2 direction. The third side S3may be formed of discontinuous inclined sides. The third surface S34connecting the third side S3 between the regions A11 to A14 iscorresponded to the second side S2, may be disposed in parallel with thesecond side S2, and is not limited thereto

The first region A11 is disposed in the first light emitting diode 34Aand the lower portion of the region adjacent to the first light emittingdiode 34A, the fourth region A14 is disposed on the second lightemitting diode 34B and the lower portion of the region adjacent to thesecond light emitting diode 34A, and the second and third regions A12and A13 are disposed on the third light emitting diode 34C and the lowerportion of the region adjacent to the third light emitting diode 34C.

The area of the top surface 131-3 of the heat radiation portion 32B mayhave the widths D1, D2, D3 and D4 different according to each of theregions A11, A14, A12, and A13. For example, the width D3 of the firstregion A12 is formed wider than the width D1 of the first region A11,the width D4 of the third region A13 is formed wider than the width D3of the second region A12, the width D2 of the fourth region A14 is thewidest and formed wider than the width D3 of the second region A12.

In the light emitting module, the area of the heat radiation portion 32Bmay be different according to the regions A11 to A14, thereby to provideheat stability of the light emitting diode 34 for each regions A11 toA14. In the embodiment, four regions are disposed as step structures,but it is possible to form the region in three or more, and is notlimited thereto. Further, the lengths of each of the regions A11 to A14are the same or different from each other, for example, the length ofthe fourth region A14 may be formed as the longest length. At least oneof each of the regions A11 to A14 may be formed with the unevenstructure, and is not limited thereto.

FIG. 8 is a prospective view showing the light emitting module accordingto a fourth embodiment.

Referring to FIG. 8, the heat radiation portion 32B of the lightemitting module 32 includes a first region A21 and fifth region A25having a first width D1, a third region A23 having a second width D2between the first and fifth regions A21 and A25, a second region A22connecting the first region A21 and the third region A23 and having theinclined surface S31, and a fourth region A24 connecting the thirdregion A23 and the fifth region A25 and having the inclined surface S33.Here, the first, third and fifth regions A21, A23 and A25 may be regionsin which at least two light emitting diodes are disposed, the second andfourth regions A22 and A24, which is the region having the area smallerthan the area of the third region A23, may be regions in which at leastone light emitting diodes is disposed, but is not limited thereto.

In the top surface 131-4 of the heat radiation portion 32B of the lightemitting module 32, the area and width of the center region, that is,the third region A23 is disposed wider as compared with other regions,and it may be prevented that the heat generated from the plurality oflight emitting diodes 34 disposed on each of the regions A21, A22, A23,A24 and A25 affects other regions, for example, the light emittingdiodes in the UP direction.

Here, the gap between the third light emitting diode 34C disposed on thecenter of the light emitting module 32 and the third side S3 of the heatradiation portion S3 may be disposed wider than the interval between thefirst and second light emitting diodes 34A and 34B disposed on the downand up direction rather than the center and the third side S3 of theheat radiation portion. The interval between the center of the wiringportion 32A and the third side S3 of the heat radiation portion 32B maybe disposed wider than the interval between the first and second regionsof the wiring portion 32A and the third side S3 of the heat radiationportion 32B. The light emitting module 32 allows the heat ascending fromthe direction opposite to the up direction to the up direction toheat-radiate by the center region of the light emitting module 32, thatis, the third region A23 and the region adjacent to the same, that is,the heat radiation portion 32B of the second and fourth regions A22 andA24, and therefore, the second light emitting diode 34B disposed on thefifth region A25 may be operated without subjecting to interferencecaused by the heat transferred from the lower portion of the thirdregion A23.

For another example, the third region A23 of the heat radiation portion32B may be formed with the uneven structure, and the uneven structuremay be formed in the shape of the stripe or the polygon. The thirdregion A23 of the heat radiation portion 32B may be formed with theuneven structure, thereby to increase the area of the heat radiation.

FIG. 9 is a side cross-sectional view showing an example of the lightemitting device of the embodiment.

Referring to FIG. 9, the light emitting diode 34 includes a body 210having a first cavity 260, a first lead frame 221 having a second cavity225, a second lead frame 231 having a third cavity 235, and lightemitting chips 271 and 272, and wires 201.

The body 210 may be made of at least one of resin material such aspolyphthalamide (PPA), silicon (Si), metal material, photo sensitiveglass (PSG), sapphire (Al₂O₃), and printed circuit board (PCB).Preferably, the body 210 may be made of the resin material such aspolyphthalamide (PPA).

The shape of the top of the body 210 may have various shapes such astriangles, rectangles, and polygons according to use and design of thelight emitting device package. The first lead frame 221 and the secondlead frame 231 are disposed under the body 210 and may be mounted on thesubstrate in a direct lighting type. The first lead frame 221 and thesecond lead frame 231 are disposed on the side of body 210 and may bemounted on the substrate in an edge type, but is not limited thereto.

The top of the body 210 is opened, and has a first cavity 260 forming aside and lower surfaces. The first cavity 260 may include a concave cupor a recess structure from the top 215 of the body 210, and is notlimited thereto. The side of the first cavity 260 may be vertical orinclined to the bottom of the first cavity 260. The shape of the firstcavity 260 as seen from the top surface may be a circle, ellipse,polygon (for example, quadrangle). A corner of the first cavity 260 maybe the curved surface or a flat surface.

The first lead frame 221 is disposed on the first region of the firstcavity 260, and the portion of the first lead frame 221 is disposedunder the first cavity 260. A concave second cavity 225 is disposed tohave a depth lower than the bottom of the first cavity 260 in the centerthereof. The second cavity 225 is a concave shape from the top surfaceof the first lead frame 221 to the lower surface of the body 210, andincludes, for example, the cup structure or the recess shape. The sideof the second cavity 225 is inclined or may be vertically folded to thebottom of the second cavity 225. Two sides facing each other among theside of the second cavity 225 may be inclined at the same angle or atdifferent angle from each other.

The second lead frame 231 is disposed on the second region to be spacedapart from the first region of the first cavity 260, and the portion ofthe second lead frame 231 is disposed under the first cavity 260. Aconcave third cavity 235 is formed to have a depth lower than the bottomof the first cavity 260 in the center thereof. The third cavity 235 is aconcave shape from the top surface of the second lead frame 231 to thelower surface of the body 210, and includes, for example, the cupstructure or the recess shape. The side of the third cavity 235 isinclined or may be vertically folded to the bottom of the third cavity235. Two sides facing each other among the side of the third cavity 235may be inclined at the same angle or at different angle from each other.

The lower surfaces of the first lead frame 221 and the second lead frame231 are exposed to the lower surface of the body 210, or may be arrangedon the same plane as the lower surface of the body 210. A gap 219between the first lead frame 221 and the second lead frame 231 may bedisposed on the center, and at least portion of it may be in contactwith the top surfaces of the first lead frame 221 and the second leadframe 231. The end of the first lead frame 221 and the second lead frame231 being in contact with the gap 219 may be formed with humiditypreventing patterns such as the step structure or/and the unevenpattern, and is not limited thereto.

The first lead portion 223 of the first lead frame 221 is disposed onthe lower surface of the body 210, and may be protruded under the firstside 213 of the body 210. A second lead portion 233 of the second leadframe 231 is disposed on the lower surface of the body 210, and may beprotruded under a second side 214 opposite to the first side of the body210.

The first lead frame 221 and the second lead frame 231 may contain atleast one of metal material, for example, titanium (Ti), copper (Cu),nickel (Ni), gold (Au), chromium (Cr), tantalnyum (Ta), platinum (Pt),tin (Sn), silver (Ag), phosphorus (P), may be formed of a single metallayer or multilayer metal layers. The thickness of the first and secondlead frames 221 and 231 may be formed as the same thickness, and is notlimited thereto.

The bottom shape of the second cavity 225 and the third cavity 235 maybe rectangle, square, or circle or ellipse having the curved surface.

The body 210 is further disposed with the other metal frame except thefirst and second lead frames 221 and 231 to use as the heat radiationframes or intermediate connecting terminals. The first and second leadframes 221 and 231 are spaced apart from each other by the gap 219, andsupports the space between the first and second lead frames 221 and 231.The top surface of the gap 219 is the same as or may be protruded highlyfrom the top surface of the first and second lead frames 221 and 231,and is not limited thereto.

The first light emitting chip 271 is disposed on the second cavity 225of the first lead frame 221, and the second light emitting chip 272 isdisposed on the third cavity 235 of the second lead frame 231. The lightemitting chips 271 and 272 may be selectively emit among the range fromvisible light band to ultraviolet light band, and may be selected among,for example, a red LED chip, a blue LED chip, a green LED chip and ayellow green LED chip. The light emitting chips 271 and 272 includescompound semiconductor light emitting device of group III to V element.

A molding member 290 is disposed in at least one region among the firstcavity 260 of the body 210, the second cavity 225 and the third cavity235. The molding member 290 includes a transmissive resin layers such assilicon or epoxy in one or a plurality of. A phosphor changingwavelengths of the light to be emitted may be included in the moldingmember 290 or the light emitting chips 271 and 272, some of the lightemitted from the light emitting chips 271 and 272 is excited by thephosphor and is emitted as the light having different wavelengths. Thephosphor may be selectively formed among YAG, TAG, silicate, nitride,and oxy-nitride-based material. The phosphor may include at least one ofred, yellow and green phosphors, and is not limited thereto. The surfaceof the molding member 290 may be formed as flat, concave and convexshape etc. and is not limited thereto.

The lens may be further formed on the top of the body 210, the lens mayinclude the structure of concave or/and convex lens, and lightdistribution of the light emitted by the light emitting device may becontrolled.

The first light emitting chip 271 may be connected to the first leadframe 221 and the second lead frame 231 disposed on the bottom of thefirst cavity 260, and the connection method thereof uses the wires 201,die bonding or flip bonding type. The second light emitting chip 272 maybe electrically connected to the first lead frame 221 and the secondlead frame 231 disposed on the bottom of the first cavity 260, and theconnection method thereof uses the wires 201, die bonding or flipbonding type.

The protection device may be arranged in the predetermined region of thefirst cavity 260, the protection device may be implemented by athyristor, a zener diode or transient voltage suppression (TVS), thezener diode protects the light emitting chip from electro staticdischarge (ESD).

The light emitting module of the embodiment may be applied to backlightunits such as portable terminal and computer, and illumination systemssuch as lighting, traffic lights, vehicle headlight, electronic displayand streetlamp, and is not limited thereto. Further, the light emittingof direct lighting type may not be disposed with the light guide plate,and is not limited thereto. Further, a transmissive materials such aslens or glass may be disposed on the light emitting module, and is notlimited thereto.

The present invention is not limited by the above-described embodimentand the accompanying drawings, and is limited by the attached claims. Inaddition, although the preferred embodiments of the present inventionare shown and described above, the present invention is not limited toabove-described specific embodiment and is variously modified by oneskilled in the art without the gist of the present invention claimed inthe claim, such that the modified embodiment is not to be understoodseparately from technical ideas or views of the present invention.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effects such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A light emitting module, comprising: a pluralityof light emitting diodes; and a module substrate including a wiringportion disposed with the plurality of light emitting diodes andelectrically connected to the plurality of light emitting diodes, and aheat radiation portion folded from the wiring portion and disposed underthe plurality of light emitting diodes, wherein the plurality of lightemitting diodes includes a first light emitting diode disposed on afirst outer region of the wiring portion, a second light emitting diodedisposed on a second outer region of the wiring portion, and a thirdlight emitting diode disposed on a center of the wiring portion, whereina width between the center of the wiring portion and an end of the heatradiation portion is wider than a distance between the first outerregion of the wiring portion and the end of the heat radiation portion,in the heat radiation portion of the module substrate, wherein thewiring portion of the module substrate includes a metal layer, a wiringlayer on the metal layer, and an insulating layer between the metallayer and the wiring layer, wherein the heat radiation portion isextended from the metal layer, and the heat radiation portion is spacedapart from the insulating layer and the wiring layer, and wherein thewiring layer is electrically connected to the plurality of the lightemitting diodes, wherein the metal layer of the wiring portion is bentfrom the heat radiation portion in a substantially vertical direction,wherein the metal layer of the wiring portion has a same thickness asthe heat radiation portion, wherein an entire region of the heatradiation portion is formed of the same metal layer as the metal layerof the wiring portion, and wherein the heat radiation portion has awidth wider than a width of the metal layer of the wiring portion. 2.The light emitting module according to claim 1, wherein the heatradiation portion of the module substrate includes a first side, asecond side opposite to the first side, and a third side being the endof the heat radiation portion and disposed between the first side andthe second side, and a width of the first side of the heat radiationportion is narrower than an interval between the center of the wiringportion and the third side, wherein the heat radiation portion includesa first region adjacent to the first light emitting diode, a secondregion adjacent to the second light emitting diode and a third regionadjacent to the third light emitting diode, wherein a heat radiationarea of the third region of the heat radiation portion is greater than aheat radiation area of the first region of the heat radiation portion.3. The light emitting module according to claim 2, wherein the secondside of the heat radiation portion has a width wider than that of thefirst side of the heat radiation portion, wherein a width of the heatradiation portion is gradually disposed widely in a direction toward thesecond light emitting diode from the first light emitting diode, whereinthe second region has a heat radiation area of the second region of theheat radiation portion greater than the heat radiation area of the firstregion of the heat radiation portion.
 4. The light emitting moduleaccording to claim 2, wherein the second side of the heat radiationportion has a width the same as that of the first side of the heatradiation portion, wherein the heat radiation area of the third regionof the heat radiation portion is greater than the heat radiation areasof the first region and the second region.
 5. The light emitting moduleaccording to claim 2, wherein an interval between the second outerregion of the wiring portion and the third side of the heat radiationportion is wider than an interval between the center of the wiringportion and the third side of the heat radiation portion, wherein theheat radiation area of the third region of the heat radiation portion issmaller than the heat radiation area of the second region of the heatradiation portion.
 6. The light emitting module according to claim 2,wherein an interval between the center of the wiring portion and thethird side of the heat radiation portion is wider than an intervalbetween the second outer region of the wiring portion and the third sideof the heat radiation portion, wherein the heat radiation area of thethird region of the heat radiation portion is greater than the heatradiation area of the second region of the heat radiation portion. 7.The light emitting module according to claim 2, wherein the third sideof the heat radiation portion is formed of a surface inclined withrespect to the first side and the second side of the heat radiationportion.
 8. The light emitting module according to claim 2, wherein thethird side of the heat radiation portion includes a fourth sidecorresponding to the second side of the heat radiation portion, whereinthe fourth side is adjacent to the third light emitting diode.
 9. Thelight emitting module according to claim 2, wherein the third side ofthe heat radiation portion includes a fifth side vertical to the firstor second side of the heat radiation portion.
 10. The light emittingmodule according to claim 7, wherein the inclined surface of the thirdside of the heat radiation portion is spaced apart from at least one ofthe first and second sides of the heat radiation portion, wherein alength of the heat radiation portion is lengthily disposed to be closerto the wiring portion than the end of the heat radiation portion,wherein the length of the heat radiation portion is an interval betweenthe first side and the second side of the heat radiation portion. 11.The light emitting module according to claim 1, wherein a thickness ofthe wiring portion is thicker than a thickness of the heat radiationportion.
 12. A light emitting module, comprising: a plurality of lightemitting diodes; and a module substrate including a wiring portiondisposed with the plurality of light emitting diodes and electricallyconnected to the plurality of light emitting diodes, and a heatradiation portion folded from the wiring portion and disposed under theplurality of light emitting diodes, wherein the plurality of lightemitting diodes includes a first light emitting diode disposed on afirst outer region of the wiring portion, a second light emitting diodedisposed on a second outer region of the wiring portion, and a thirdlight emitting diode disposed on a center of the wiring portion, whereina width between the center of the wiring portion and an end of the heatradiation portion is wider than a distance between the first and secondouter regions of the wiring portion and the end of the heat radiationportion, in the heat radiation portion of the module substrate, whereinthe wiring portion of the module substrate includes a metal layer, awiring layer on the metal layer, and an insulating layer between themetal layer and the wiring layer, wherein the heat radiation portion isextended from the metal layer, wherein a top surface of the heatradiation portion is spaced apart from the insulating layer and thewiring layer, and wherein the wiring layer includes a circuit pattern,and the wiring layer is electrically connected to the plurality of thelight emitting diodes, wherein the metal layer of the wiring portion isbent from the heat radiation portion in a substantially verticaldirection, wherein the metal layer of the wiring portion has a samethickness as the heat radiation portion, wherein an entire region of theheat radiation portion is formed of the same metal layer as the metallayer of the wiring portion, wherein the heat radiation portion has awidth wider than a width of the metal layer of the wiring portion,wherein a length of the heat radiation portion is lengthily disposed tobe closer to the wiring portion than the end of the heat radiationportion, and wherein the length of the heat radiation portion is aninterval between a first side and a second side of the heat radiationportion.
 13. The light emitting module according to claim 12, wherein athickness of the wiring portion is thicker than a thickness of the heatradiation portion.
 14. A backlight unit, comprising: a bottom coverincluding a bottom portion, and a first side portion folded from thebottom portion; a light guide plate disposed on the bottom portion ofthe bottom cover; and a light emitting module comprising a modulesubstrate including a wiring portion disposed on an inside of the firstside portion of the bottom cover and corresponding to at least one sideof the light guide plate, and a heat radiation portion folded from thewiring portion and disposed on the bottom portion of the bottom cover;and a plurality of light emitting diodes disposed on the wiring portionof the module substrate and corresponding to at least one side of thelight guide plate, wherein the plurality of light emitting diodesincludes a first light emitting diode disposed on a first outer regionof the wiring portion, a second light emitting diode disposed on asecond outer region of the wiring portion, and a third light emittingdiode disposed on a center of the wiring portion and corresponding to acenter of the at least one side of the light guide plate, wherein awidth between the center of the wiring portion and an end of the heatradiation portion is wider than a distance between the first outerregion of the wiring portion and the end of the heat radiation portion,in the heat radiation portion of the module substrate, wherein the heatradiation portion is disposed under a bottom surface of the light guideplate, wherein the wiring portion of the module substrate includes ametal layer, a wiring layer on the metal layer, and an insulating layerbetween the metal layer and the wiring layer, wherein the heat radiationportion is extended from the metal layer, and the heat radiation portionis spaced apart from the insulating layer, and wherein the wiring layerincludes a circuit pattern, and the wiring layer is electricallyconnected to the plurality of the light emitting diodes, wherein themetal layer of the wiring portion is bent from the heat radiationportion in a substantially vertical direction, wherein the metal layerof the wiring portion has a same thickness as the heat radiationportion, wherein an entire region of the heat radiation portion isformed of the same metal layer as the metal layer of the wiring portion,wherein an entire top surface of the heat radiation portion has an areasmaller than an area of a bottom surface of the light guide plate, andwherein the heat radiation portion has an area smaller than an area ofthe bottom portion of the bottom cover.
 15. The backlight unit accordingto claim 14, further comprising a connecting member between the modulesubstrate and the side portion and the bottom portion of the bottomcover, wherein the connecting member includes an adhesive member. 16.The light emitting module according to claim 1, wherein the wiringportion includes a protection layer on the wiring layer having a circuitpattern.
 17. The light emitting module according to claim 2, wherein thefirst region, the second region and the third region have a widthsdifferent from each other, and wherein the first region, the secondregion and the third region of the heat radiation portion have a heatradiation areas different from each other.
 18. The backlight unitaccording to claim 14, wherein the heat radiation portion has a widthwider than a width of the metal layer of the wiring portion.
 19. Thebacklight unit according to claim 14, wherein the bottom portionincludes a recess concaved from a part of a top surface of the bottomportion, wherein the heat radiation portion is disposed in the recess ofthe bottom portion of the bottom cover.
 20. The backlight unit accordingto claim 19, further comprising a first adhering member adhered betweenthe metal layer of the wiring portion and the first side portion of thebottom cover, and a second adhering member adhered between the heatradiation portion and a surface in the recess.